treewide: define and use macro IN6_IS_ADDR_ULA

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

3 files changed, 4 insertions, 3 deletions

diff --git a/src/ndp.c b/src/ndp.c
index 427547d..5866588 100644
--- a/src/ndp.c
+++ b/src/ndp.c
@@ -328,8 +328,8 @@ static void setup_route(struct in6_addr *addr, struct interface *iface, bool add
 static int prefixcmp(const void *va, const void *vb)
 {
 	const struct odhcpd_ipaddr *a = va, *b = vb;
-	uint32_t a_pref = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
-	uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
+	uint32_t a_pref = IN6_IS_ADDR_ULA(&a->addr) ? 1 : a->preferred;
+	uint32_t b_pref = IN6_IS_ADDR_ULA(&b->addr) ? 1 : b->preferred;
 	return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
 }
 
diff --git a/src/odhcpd.h b/src/odhcpd.h
index fb78ec0..ceef0bf 100644
--- a/src/odhcpd.h
+++ b/src/odhcpd.h
@@ -57,6 +57,7 @@
 #define ALL_IPV6_ROUTERS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
 		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02}}}
 
+#define IN6_IS_ADDR_ULA(a) (((a)->s6_addr32[0] & htonl(0xfe000000)) == htonl(0xfc000000))
 
 struct interface;
 struct nl_sock;
diff --git a/src/router.c b/src/router.c
index e11fa01..36267be 100644
--- a/src/router.c
+++ b/src/router.c
@@ -309,7 +309,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add
 		uint32_t this_lifetime = TIME_LEFT(addr->valid, now);
 		if (this_lifetime > UINT16_MAX)
 			this_lifetime = UINT16_MAX;
-		if (((addr->addr.s6_addr[0] & 0xfe) != 0xfc || iface->default_router)
+		if ((!IN6_IS_ADDR_ULA(&addr->addr) || iface->default_router)
 				&& adv.h.nd_ra_router_lifetime
 				&& ntohs(adv.h.nd_ra_router_lifetime) < this_lifetime) {
 			adv.h.nd_ra_router_lifetime = htons(this_lifetime);